Suggest FTP server and a client

Hello.
For business we have an internal network using gigabit speed.
We need to transfer about 200 gb per day, each new day means a new 200 gb.
We have d-link switch gigabit and cat6 cables and d-link network pci cards.
Please for best fast transfer rate as possible, what is the server and a client you would recommend most?
Please advise as this is really urgent.
Thanks